JP2725393B2 - Clothes dryer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller for a clothes dryer capable of drying an object to be dried having a low heat-resistant temperature, such as a blanket.

2. Description of the Related Art Conventionally, when a cloth or a clothes having a low heat-resistant temperature such as a blanket is dried with a clothes dryer, the temperature of the cloth does not rise due to moisture generated from the cloth when the cloth is moist, so that heat is not generated. Although there is no adverse effect on the cloth or the like, as the cloth or the like approaches drying, the humidity decreases and the temperature of the cloth or the like increases, so that the hot air causes discoloration, deformation, and shrinkage of the fiber of the cloth or the like. Therefore, in a conventional clothes dryer, an object to be dried having a low heat-resistant temperature such as a blanket is not dried.

Problems to be Solved by the Invention However, the conventional clothes dryer cannot dry the object to be dried having a low heat-resistant temperature, so it has to be dried in the sun. For example, there has been a problem that a large drying place is required to dry a blanket or the like, and the drying operation is difficult.

SUMMARY OF THE INVENTION In view of the above-described problems, a first object of the present invention is to make it possible to dry an object to be dried having a low heat-resistant temperature such as a blanket with a clothes dryer.

A second object is to make it possible to control the output of the heating means with high accuracy and to reliably dry an object to be dried having a low heat-resistant temperature.

A third object is to prevent an object to be dried having a low heat-resistant temperature from being raised to a high temperature due to an erroneous operation.

A fourth object is to perform high-precision drying control corresponding to room temperature.

Means for Solving the Problems A first technical means of the present invention for achieving the first object is a heating means for supplying hot air into a drum, and detecting a temperature of air discharged from the drum. Discharge temperature detecting means, a room temperature detecting means for detecting room temperature, a control means for controlling the heating means and the like based on a temperature difference between the discharge temperature detecting means and the room temperature detecting means to perform drying control, and a plurality of drying means. When a blanket course is set by the course setting means, the control means sets a temperature difference between the discharge temperature detecting means and the room temperature detecting means to a predetermined value after maintaining a constant value. After reaching a predetermined value which is larger than the predetermined value, the heating means is configured to reduce the energization ratio and drive for a predetermined time.

A second technical means of the present invention for achieving the second object is a heating means for supplying hot air into a drum, and a discharge temperature detecting means for detecting a temperature of air discharged from the drum. A dehumidifying temperature detecting means for detecting a temperature of air discharged from the drum after dehumidifying; a room temperature detecting means for detecting room temperature; and the heating means based on a temperature difference between the exhaust temperature detecting means and the dehumidifying temperature detecting means. Control means for controlling drying and the like, and course setting means for setting a plurality of drying control courses. When the blanket course is set by the course setting means, the control means sets the discharge temperature detection means and the dehumidification After the temperature difference with the temperature detecting means reaches a predetermined value larger than the predetermined value after maintaining the fixed value, the power supply ratio of the heating means is reduced and the heating means is driven for a predetermined time. It is intended.

A third technical means of the present invention for achieving the third object is that, when a blanket course is set by the control means,
The configuration is such that the setting content of the heating output setting means is not accepted.

A fourth technical means for achieving the fourth object is as follows.
The control means is configured to determine a predetermined value of the temperature difference between the two temperature detection means based on the room temperature.

According to the first technical means, when the temperature difference between the room temperature and the discharge temperature discharged from the drum reaches a predetermined value, the output of the heating means is reduced, so that the object to be dried in the drum is exposed to a high temperature. Without drying, an object to be dried such as a blanket can be dried by a clothes dryer. More specifically, when the object to be dried is moist, the temperature discharged from the drum becomes constant even if heat is supplied from the heating means, and the water gradually evaporates from the object to be dried. Next, when the amount of evaporation of water from the material to be dried is reduced, the temperature of the discharge discharged from the drum rises. Therefore, the output of the heating means is reduced near the start of the rise. The detection in the vicinity of the start of the rise of the discharge temperature detects how much the discharge temperature has risen compared to the room temperature (the temperature difference between the room temperature and the discharge temperature). Then, at the time of the detection, the output of the heating means is reduced to prevent the temperature in the drum from rising, and the thermal influence on the dried object having a low heat-resistant temperature can be suppressed.

According to the second technical means, the point of time when the output of the heating means is reduced is determined based on the temperature difference between the discharge temperature of the air discharged from the drum and the dehumidification temperature of the discharged air after dehumidification. Control can be performed. That is,
The discharge temperature starts to increase when the amount of water evaporation of the material to be dried decreases, while the dehumidification temperature starts to decrease, so that the change in the temperature difference between the discharge temperature and the dehumidification temperature is large. The detection accuracy at the time of the drop switching can be increased.

According to the third technical means, when the temperature difference between the two temperature detecting means (the temperature difference between the room temperature and the discharge temperature or the temperature difference between the discharge temperature and the dehumidification temperature) reaches a predetermined value, the output of the heating means is reduced. If the drying control course to be set is set, the setting content of the output setting means of the heating means is ignored, so even if the user sets the heating output by mistake and then sets the drying control course, the temperature difference becomes a predetermined value. Since the output of the heating means is reliably reduced when the temperature reaches the predetermined value, it is possible to prevent the drying operation from proceeding with the heating means set to a high output due to the erroneous operation of the user.

According to the fourth technical means, the temperature difference between the room temperature and the discharge temperature or the temperature difference between the discharge temperature and the dehumidification temperature is detected, and the predetermined value (the determination value at the time of switching the output of the heating means) is determined according to the room temperature. Because of the change, correction can be made to the temperature difference that fluctuates under the influence of room temperature, and highly accurate drying control can be performed.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a basic configuration of a clothes dryer and a control device thereof will be described with reference to FIGS.

In the figure, reference numeral 1 denotes an AC power supply, to which a motor 2 and heaters 3 and 4 as heating means are connected respectively. The motor 2 and the heaters 3 and 4 are supplied with power from the AC power supply 1 via bidirectional thyristors 5, 6 and 7, which are a kind of switching element. The motor 2 rotationally drives a drum 23 rotatably disposed in the main body of the clothes dryer and a heat exchange type blower 24 disposed behind the drum 23. Heat exchange type blower 24
Generates the circulating air A and the cooling air B indicated by the arrows in FIG. 2 and exchanges heat between the circulating air A and the cooling air B to condense moisture contained in the circulating air discharged from the drum 23. ,
Discharge outside the machine from the drain 25. That is, the heat exchange blower 24 functions as a dehumidifying unit that removes the moisture of the circulating air A. The circulating air after dehumidification of the heat exchange type blower 24 is heated again by the heater 3 and supplied into the drum 23. Further, temperature detecting means 16 is provided at various points in the clothes dryer. Discharge temperature detecting means 17 for detecting the temperature of the circulating air A discharged from the drum 23, dehumidifying temperature detecting means 18 for detecting the temperature of the circulating air A dehumidified by the heat exchange type blower 24, and the temperature of the cooling air B Room temperature detection means for detecting and detecting room temperature
19 and has. These temperature detecting means 16 are specifically, for example, a temperature thermistor or the like. Temperature detection means 16
Is converted into a digital signal by the A / D converter 20 and input to the operation control unit 21 composed of a microcomputer or the like. The operation control unit 21 receives a signal from the input setting unit 11. The input setting unit 11 includes an output setting switch 12 serving as heating output setting means for setting the intensity of the output of the heaters 3 and 4.
And a course setting switch 13 which is a course setting means for setting a plurality of drying control courses, and a start / pause switch 14 for starting and temporarily stopping the drying operation. On the other hand, a display unit 22 is provided on the output side of the operation control unit 21.
And the load drive unit 15 are connected. Load driver 15
Is composed of transistors 8, 9, and 10 for controlling the switching of the bidirectional thyristors 5, 6, and 7 for controlling the energization of the motor 2, the heaters 3 and 4. The display unit 22 is the third
As shown in the figure, the strength states of the heaters 3 and 4 set by the output setting switch 12 and the drying course (standard course and blanket course) set by the course setting switch 13 are displayed.

Next, a first embodiment of the present invention will be described based on the configuration and control device of the above-mentioned basic clothes dryer and FIGS. 4 to 6.

In this embodiment, in order to dry a blanket, which is a material to be dried having a low heat-resistant temperature, first, as shown in FIG.
To set the blanket course, and then press the start / pause switch 14 in step 31. In response to the start signal, the operation control 21 causes the load drive unit 15 to operate the signal feed motor 2 and the heaters 3 and 4 in step 32. Then operation control
21 inputs the discharge temperature from the discharge temperature detecting means 17 in step 33 and the room temperature from the room temperature detecting means 19 in step 33;
In calculating the temperature difference between the exhaust temperature and the room temperature, it determines whether the temperature difference reaches a predetermined value T _0. If the temperature difference has not reached the predetermined value T ₀ , the above control is repeated, and if the temperature difference has reached the predetermined value T ₀ , the energization of the heater 3 is stopped in step 35. In other words,
The heating means is set to a low output state by only the heater 4, and this state is maintained for a predetermined time in step 36. Further steps
At 37, the heater 4 is also turned off, and a cold air operation is performed in which only the motor 2 in step 38 is operated for a predetermined time. After performing this cool air operation for a predetermined time, the motor 2 is turned off in step 39, and the operation is terminated in step 40.

In Figure 5 shows the change with drying time between room temperature T ₂ of the from the exhaust temperatures T ₁ and room temperature detecting means 19 from the discharge temperature detecting means 17. In the section A in the figure, a constant discharge temperature is maintained in the process of gradually evaporating the moisture from the object to be dried. Section B is a process in which the amount of heat used for evaporating the moisture of the object to be dried decreases as the moisture in the object to be dried decreases, and the discharge temperature starts to rise. In this embodiment, as shown in FIG. 6, the discharge temperature T ₁
And which detects the temperature difference between the room temperature T _2, the discharge temperature as the temperature difference was the lower the OFF heated outputs the energization of the heater 3 when it reaches a predetermined value T _0, C section of FIG. Lower. Therefore, the temperature in the drum 23, which is correlated with the discharge temperature, can be reduced, and the heat effect on the object to be dried in the drum 23 can be suppressed. It can be dried with a clothes dryer without any problems.

Here, the reason for performing the drying control based on the temperature difference between the discharge temperature and the room temperature is that when the room temperature is high, the discharge temperature is high, while when the room temperature is low, the discharge temperature is low. If an attempt is made to detect the decrease point, an error occurs in the detection point due to the influence of the room temperature, and the object to be dried may be exposed to a high temperature state.

In the above-described embodiment, the point at which the heating output is reduced is detected at a constant predetermined value T ₀ regardless of the room temperature. However, as shown in FIG. 7, when the predetermined value T ₀ is changed according to the room temperature, It is possible to detect the heating output lowering point with higher accuracy than in the embodiment.
That is, although the temperature difference shown in FIG. 6 is the difference between the discharge temperature and the room temperature, since the discharge temperature has a high rate of increase in the room temperature, the predetermined value is changed according to the room temperature and the predetermined value is changed regardless of the room temperature. When the drying rate (90-95%) is reached, the heating output is switched, and the object to be dried having a low heat-resistant temperature can be dried without being affected by room temperature.

Next, a second embodiment of the present invention will be described based on the configuration and control device of the above-mentioned basic clothes dryer and FIGS. 8 and 9.

In this embodiment, the dehumidification temperature detecting means 18 is used in place of the room temperature detecting means 19 of the first embodiment, and the basic drying control is the same as that of the first embodiment. That is, a temperature difference between the discharge temperature from the discharge degree temperature detection means 17 and the dehumidification temperature from the dehumidification temperature detection means 18 dehumidified by the heat exchange type blower 24 is detected, and when this temperature difference reaches a predetermined value Ta. This reduces the heating output. As shown in FIG. 8, the dehumidification temperature T ₃
, Upon transition from section A to section B, it continues to temperature drop contrary to the temperature T _1. Therefore, the rate of change of the temperature difference (T ₁ −T ₃ ) between the discharge temperature T ₁ and the dehumidification temperature T _{3 in} section B becomes large as shown in FIG. 9, and the discharge temperature and room temperature of the first embodiment are different from each other. It can be seen that the rate of change is large even when compared with the rate of change of the temperature difference. If it is determined whether or not the temperature difference has reached the predetermined value Ta in the portion where the change rate is large, it is possible to detect the arrival time of the predetermined value Ta with high accuracy.

In the second embodiment, the time point at which the heating output is reduced is detected at a constant predetermined value Ta regardless of the room temperature.
As shown in FIG. 10, when the predetermined value Ta is changed in accordance with the room temperature, a time point at which the heating output decreases with higher accuracy than in the above embodiment can be detected. That is, the temperature difference shown in FIG. 9 is greatly affected by the room temperature. If the room temperature is high, the cooling effect of the heat exchange type blower 24 is low, while if the room temperature is low, the cooling effect of the heat exchange type blower 24 is high, so the dehumidification temperature detection after the dehumidification by the heat exchange type blower 24 is performed. The dehumidification temperature from the means 18 will be greatly affected by the room temperature. Therefore,
As shown in FIG. 10, the operation control unit 21 includes a room temperature detecting unit 19.
Is input to change the predetermined value Ta of the temperature difference between the discharge temperature detecting means 17 and the dehumidifying temperature detecting means 19.

In the first and second embodiments, the heating output is reduced by turning on and off the power to the heaters 3 and 4 as the heating means. For example, as shown in FIG. ,
The control method of changing the energization ratio of No. 4 may be used. That is, until the temperature difference reaches a predetermined value T ₀ or Ta Figure 11 a
The heaters 3 and 4 are fully energized as shown in
T ₀ or the drawing b reaches Ta, may reduce the power energization percentage, as shown to c.

Next, a third embodiment of the present invention will be described with reference to FIG. First, in step 41, it is determined whether or not the blanket course has been set by the course setting switch 13, and if the blanket course has been set, it is determined in step 42 whether or not the start / pause switch 14 has been turned ON. If the start / pause switch 14 is ON, the setting content of the heating output is ignored in step 43, and the blanket course is executed in step 44.
If the start / pause switch 14 is not turned on in step 42, the process returns to step 41 again. If it is determined in step 41 that the blanket course has not been set, step 45
Determines the strength of the heating output of the heaters 3 and 4. If the heating output is set to a high level, the start / pause switch 14 is turned on in steps 46 and 47 and the heaters 3 and 4 serving as heating means are turned on.
Is operated at high setting. If it is determined in step 45 that the heating output is weak, the start / pause switch 14 is turned on in steps 48 and 49.
4 is operated at a weak setting. Start at steps 46 and 48 /
If the pause switch 14 is not turned on, the process returns to the blanket course setting determination of step 41.

If the blanket course is set by the course setting switch 13 as described above, the setting content of the output setting switch 12 is ignored, so that even if the user mistakenly sets the blanket course with the heating output set strongly, it is inappropriate. The blanket course operation is continued by the strong heating, and the thermal damage of the blanket, which is a material to be dried having a low heat-resistant temperature, can be prevented.

Effects of the Invention As is clear from the above embodiments, the present invention has the following effects.

(1) When the temperature difference between the discharge temperature and room temperature reaches a predetermined value,
In order to perform drying control to reduce the output of the heating means, it is possible to prevent the object to be dried having a low heat-resistant temperature such as a blanket from being exposed to a high temperature, and to dry the object to be dried having a low heat-resistant temperature with a clothes dryer. Shrinkage due to heat or heat damage can be eliminated.

(2) Since the temperature difference between the discharge temperature and the dehumidification temperature is used to detect the time point at which the heating output is reduced, the amount of change in the temperature difference near the time point of detection becomes large, and the detection accuracy can be improved, and the reliability can be improved. Can be improved.

(3) Even if the heating output is set strongly by the heating output setting means and the drying control course of the object to be dried having a low heat-resistant temperature is set,
If this drying control course is set, the setting contents of the heating output setting means are ignored, so that even if the setting is made by the above-mentioned erroneous operation, drying can be surely performed without affecting the object to be dried, and drying failure due to erroneous operation is prevented. it can.

(4) Since the predetermined value of the temperature difference that determines the point at which the heating output is reduced is changed depending on the room temperature, the predetermined value affected by the room temperature is corrected, and the heating output can be switched with high accuracy, thereby achieving stable drying control. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a clothes dryer according to a basic embodiment of the present invention, FIG. 2 is a sectional view of the clothes dryer, FIG. 3 is a front view showing an operation display unit of the clothes dryer, and FIG. FIG. 5 is a flowchart showing the operation control of the first embodiment of the present invention, FIG. 5 is a diagram showing the temperature change between the dehumidifying temperature and the room temperature of the temperature detecting means, and FIG. shows a temperature difference change of FIG. 7 shows the temperature change of the exhaust temperature and the dehumidification temperature of the temperature detecting means in the second embodiment of the relationship diagram between the room temperature and the predetermined value T _0, FIG. 8 is the invention FIG. 9, FIG. 9 is a diagram showing a temperature difference change between the discharge temperature and the dehumidification temperature of the temperature detecting means, FIG. 10 is a diagram showing a relationship between room temperature and a predetermined value Ta, FIG. FIG. 12 is a flowchart showing input control according to the third embodiment of the present invention. 2: motor, 3, 4: heater, 5, 6, 7: bidirectional thyristor, 11: input setting section, 12: output setting switch, 13: course setting switch, 14: start / pause switch, 15:
Load drive unit, 17: exhaust temperature detection unit, 18: dehumidification temperature detection unit, 19: room temperature detection unit, 21: operation control unit, 22: display unit, 23: drum, 24: heat exchange type blower.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-19299 (JP, A) JP-A-58-219000 (JP, A) JP-A-58-182077 (JP, A) 209400 (JP, A) JP-A-3-4900 (JP, A) JP-A-63-145699 (JP, A) JP-A-53-77375 (JP, A) JP-A-60-222097 (JP, A) JP-A-2-297400 (JP, A) JP-A-2-26599 (JP, A) JP-A-60-83699 (JP, A) JP-A-63-166197 (JP, U) JP-A-60-33994 (JP, U) Japanese Utility Model Showa 59-188098 (JP, U) Japanese Utility Model Showa 50-38565 (JP, U)

Claims (4)

(57) [Claims] A heating means for supplying hot air into the drum; a discharge temperature detecting means for detecting a temperature of air discharged from the drum; a room temperature detecting means for detecting a room temperature; Control means for controlling the heating means and the like by a temperature difference from room temperature detection means to perform drying control, and a course setting means for setting a plurality of drying control courses,
When the blanket course is set by the course setting means, the control means keeps a temperature difference between the discharge temperature detection means and the room temperature detection means at a predetermined value and then reaches a predetermined value larger than the predetermined value. After that, the energization ratio of the heating means is reduced, and the clothes dryer is driven for a predetermined time. 2. A heating means for supplying hot air into the drum, a discharge temperature detecting means for detecting a temperature of air discharged from the drum, and a temperature after dehumidification of the air discharged from the drum. Dehumidifying temperature detecting means, a room temperature detecting means for detecting room temperature, a controlling means for controlling the heating means and the like based on a temperature difference between the exhaust gas temperature detecting means and the dehumidifying temperature detecting means, and a plurality of drying means. When a blanket course is set by the course setting means, the control means sets the control course to a predetermined value after a temperature difference between the discharge temperature detection means and the dehumidification temperature detection means is maintained at a constant value. After reaching a predetermined value greater than a predetermined value, the clothes dryer is driven for a predetermined time by reducing the energization ratio of the heating means. 3. The control means, when the blanket course is set,
3. The clothes dryer according to claim 1, wherein the setting contents of the heating output setting means are not accepted. 4. The clothes dryer according to claim 1, wherein the control means determines a predetermined value of the temperature difference between the two temperature detecting means based on the room temperature.